The present invention relates to a sputtering target comprised of an Al—Te—Cu—Zr-based alloy and a method of manufacturing the same, and in particular relates to an Al—Te—Cu—Zr-based alloy sputtering target for use in forming a thin film comprised of an Al—Te—Cu—Zr-based alloy, which is a resistive random access material, and to a method of manufacturing the same.
In recent years, thin films comprised of a Te—Al-based material or a Te—Zr-based material which record information by using resistance change are being used as a resistive random access recording material. As methods of forming thin films from the foregoing materials, normally adopted are the vacuum deposition method and the sputtering method which are generally referred to as physical deposition methods. In particular, thin films are often formed using the magnetron sputtering method in light of its operability and stability of deposition.
The formation of thin films via the sputtering method is performed by physically colliding positive ions, such as argon ions, with a target mounted on the cathode, and sputtering the material configuring the target based on the collision energy to laminate a film, which substantially has the same composition as the target material, on the substrate mounted on the cathode facing the target. Deposition via the sputtering method is characterized in that, by adjusting the treatment time and supplied power, it is possible to form thin films of angstrom units to thick films of several ten μm at a stable deposition rate.
As a Te—Al-based sputtering target, for example, Patent Document 1 discloses a target containing one or more types of high melting point metal elements selected from an element group of Ti, Zr, Hf, V, Nb, Ta, and lanthanoid elements, one or more types of elements selected from Al, Ge, Zn, Co, Cu, Ni, Fe, Si, Mg, and Ga, and one or more types of chalcogen elements selected from S, Se, and Te. Furthermore, Patent Document 1 discloses, as the method of manufacturing an AlCuGeTeZr target material, preparing an AlCuZr alloy ingot, thereafter pulverizing the alloy ingot to obtain an alloy powder, mixing the alloy powder with a Te powder and a Ge powder, and sintering the mixed powder.
When preparing a sintered body comprised of a multi-component-based alloy, the method of preliminarily synthesizing the structural components and using them as raw materials is often adopted. Nevertheless, in the case of manufacturing an Al—Te—Cu—Zr alloy, when Te—Zr are preliminarily synthesized, because the vapor pressure of Te is high, there is a problem in that a compositional deviation will arise in the liquid phase synthesis with Zr having a high melting point (vapor pressure of Te at 1000° C. is 100 kPa, while the vapor pressure of Zr is 1 kPa or less). Furthermore, when Al and Te are alloyed, there is a problem in that a highly active and difficult-to-handle Al—Te is generated.
Furthermore, when forming a Te—Al-based alloy film as a resistive random access recording material, there is a problem in that nodules are generated on the target surface during sputtering, and cause the generation of particles and arcing. In particular, since an Al—Te—Cu—Zr alloy target is comprised of multiple metal components with different deposition rates, there is a problem in that the frequency of generation of nodules is great, and the amount of generation of particles is also consequently great. And the problems with these types of targets and the sputtering of these targets are that they considerably deteriorate the quality of the thin film as a recording medium.